HPO Phenotype Lookup

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint, which cover core behavioral expectations (safe, idempotent, open-ended results). The description adds useful context about returned content (phenotype label, definition, diseases, parent terms) and an approximate result size. However, it does not disclose any potential limitations, rate limits, or authentication requirements, leaving the agent to infer from annotations alone.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is extremely concise: three sentences of core info plus a concrete example. No redundant or vague language. It front-loads the purpose and then lists return fields in a clear bullet-like manner. Every sentence earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given that the tool has an output schema (not shown but indicated), the description need not detail return format. It covers the main return categories (phenotype label, definition, synonyms, diseases, parent terms) and provides an illustrative example. However, it omits error handling (invalid HPO ID) or pagination details for disease_limit, which would enhance completeness for an agent.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema provides descriptions for all three parameters (hpo_id, disease_limit, include_diseases) with types, defaults, and constraints. Since schema description coverage is effectively 100%, the description adds no extra semantic value for parameters beyond the example usage. Per guidelines, baseline is 3, and the description does not enhance beyond that.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the action ('Retrieve an HPO phenotype term') and the resource ('with associated disease annotations'), and lists specific return fields. The example with a concrete HPO ID and expected result ('~400 associated diseases') solidifies understanding. It naturally distinguishes itself from sibling tools like lookup_disease or search_diseases.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies usage when you have an HPO ID and want phenotype details plus associated diseases. However, it provides no explicit guidance on when to choose this tool over alternatives (e.g., lookup_disease, search_diseases), nor does it mention prerequisites or exclusion criteria. The default disease_limit and parameters hint at typical use, but direct comparison is absent.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.